Intraoperative calcium-related risk factors for biochemical acute pancreatitis after living-donor liver transplantation

Calcium administration appears not to benefit acute pancreatitis patients with hypocalcemia

OBJECTIVE

Hypocalcemia occurs commonly among patients with acute pancreatitis (AP) in the intensive care unit (ICU). Calcium therapy could be used to correct hypocalcemia and maintain calcium levels, but its impact on the prognosis has not been demonstrated. Our study aimed to determine whether calcium therapy could benefit the multiple outcomes of AP patients with hypocalcemia.

METHODS

We extracted 807 AP patients with hypocalcemia from the Beth Israel Deaconess Medical Center (MIMIC-IV) database and performed retrospective analyses. The outcomes were in-hospital, 28 days, ICU mortality, and the length of stay (LOS) in the hospital and ICU. We performed propensity matching (PSM) and inverse probability weighting (IPTW) to balance the baseline differences and conducted multivariate regression to investigate the impact of calcium therapy.

RESULTS

A total of 620 patients (76.8%) received calcium treatment (calcium group) during hospitalization, while 187 patients (non-calcium group) did not. Patients in the calcium group did not present significant survival differences between groups before and after matching. After including covariates, calcium administration had no association with patients' in-hospital (HR: 1.03, 95% Cl: 0.47-2.27, p = .942), 28 days and ICU mortality and was significantly associated with prolonged length of stay in the hospital (effect estimate: 6.18, 95% Cl: 3.27-9.09, p < .001) and ICU (effect estimate: 1.72, 95% Cl: 0.24-3.20, p < .001). Calcium therapy could not benefit patients in subgroups with exclusive parenteral infusion, early calcium therapy (<48 h), or various degrees of hypocalcemia.

CONCLUSION

AP patients with hypocalcemia could not benefit from calcium administration, which has no association with multiple mortality and is significantly associated with prolonged LOS in the hospital and ICU.

Mechanisms of Pancreatic Injury Induced by Basic Amino Acids Differ Between L-Arginine, L-Ornithine, and L-Histidine

Pancreatic acinar cells require high rates of amino acid uptake for digestive enzyme synthesis, but excessive concentrations can trigger acute pancreatitis (AP) by mechanisms that are not well understood. We have used three basic natural amino acids L-arginine, L-ornithine, and L-histidine to determine mechanisms of amino acid-induced pancreatic injury and whether these are common to all three amino acids. Caffeine markedly inhibited necrotic cell death pathway activation in isolated pancreatic acinar cells induced by L-arginine, but not L-ornithine, whereas caffeine accelerated L-histidine-induced cell death. Both necroptosis inhibitors of RIPK1 and RIPK3 and a necroptosis activator/apoptosis inhibitor z-VAD increased cell death caused by L-histidine, but not L-arginine or L-ornithine. Cyclophilin D knock-out (Ppif-/-) significantly attenuated cell death induced by L-histidine, but not L-arginine, or L-ornithine. Allosteric modulators of calcium-sensing receptor (CaSR) and G-protein coupled receptor class C group 6 member A (GPRC6A) had inhibitory effects on cell death induced by L-arginine but not L-ornithine or L-histidine. We developed a novel amino acid-induced AP murine model with high doses of L-histidine and confirmed AP severity was significantly reduced in Ppif-/- vs. wild type mice. In L-arginine-induced AP neither Ppif-/-, caffeine, or allosteric modulators of CaSR or GPRC6A reduced pancreatic damage, even though CaSR inhibition with NPS-2143 significantly reduced pancreatic and systemic injury in caerulein-induced AP. These findings demonstrate marked differences in the mechanisms of pancreatic injury induced by different basic amino acids and suggest the lack of effect of treatments on L-arginine-induced AP may be due to conversion to L-ornithine in the urea cycle.

Hypocalcemia in acute pancreatitis revisited

Hypocalcemia is a frequent finding in acute pancreatitis. Severe hypocalcemia can present with neurological as well as cardiovascular manifestations. Correction of hypocalcemia by parenteral calcium infusion remains a controversial topic as intracellular calcium overload is the central mechanism of acinar cell injury in pancreatitis. The current article deals with the art and science of calcium correction in pancreatitis patients.

Effects of Liver Function on Ionized Hypocalcaemia following Rapid Blood Transfusion

OBJECTIVE: Hypocalcaemia detrimentally affects the cardiovascular system and massive transfusion-related hypocalcaemia is particularly severe in end-stage liver disease patients undergoing liver transplantation (LT). This study, therefore, compared the severity and duration of ionized hypocalcaemia between patients with normal and impaired liver function. METHODS: Patients ( n = 26 per group) were transfused at a rate of 10 ml/kg within 10 min with packed red blood cells (PRBCs) during LT (group LP) or spinal surgery (group SP), or were infused with 0.9% normal saline during spinal surgery (group SN). Serum levels of ionized calcium were assessed before (T0), just after (T1), and at 20 (T2) and 60 min (T3) after transfusion. RESULTS: Transfusion with PRBCs caused more severe ionized hypocalcaemia than 0.9% normal saline at T1. In contrast to the faster (20 min) normalization in group SP, ionized hypocalcaemia in group LP persisted at T3. Serum ionized calcium levels at T3 showed correlations with vital signs, blood glucose, serum potassium, base deficit and lactate. CONCLUSION: Rapid blood transfusion caused more severe and prolonged ionized hypocalcaemia in patients with liver dysfunction than in those with normal liver function.